EP4098588A1

EP4098588A1 - Automatic warehouse, method for controlling automatic warehouse, program, and automatic warehouse system

Info

Publication number: EP4098588A1
Application number: EP20916285.8A
Authority: EP
Inventors: Taisuke NAKO; Hiroki Morisaki
Original assignee: Murata Machinery Ltd
Current assignee: Murata Machinery Ltd
Priority date: 2020-01-30
Filing date: 2020-09-29
Publication date: 2022-12-07
Also published as: CN114945525A; WO2021152912A1; JPWO2021152912A1; JP7338708B2; EP4098588A4; US20230041684A1

Abstract

The present invention provides shelves which are provided based on the size of articles to be stored and prevents excessive access to a specific carrier.An automated warehouse includes shelves, a carrier, an elevator, and a controller. The shelves include a first shelf storing a first article and a second shelf which is larger than the first shelf and stores the first article and the second article. The carrier is provided at each shelf and transfers articles. The elevator moves articles up or down. In a case where the vacancy rate of the second shelf is equal to or more than a predetermined ratio, the controller controls the carrier and the elevator to store the first article onto the second shelf. In a case where the vacancy rate of the second shelf is less than the predetermined ratio, the controller controls the carrier and the elevator to store the first article only onto the first shelf.

Description

Technical field

The present invention relates to an automated warehouse where a plurality of shelves to store articles are provided and carriers to carry articles are installed at each shelf, a control method of the automated warehouse, a program to cause a computer to execute the control method, and an automated warehouse system including a plurality of the automated warehouses.

Background art

A known automated warehouse (hereinafter, referred to as 'an automated warehouse with a carrier installed at each shelf') includes a plurality of carriers that carry articles. Each of the carriers is installed at each of a plurality of shelves storing articles. The carrier travels on the corresponding shelf in the shelf extending direction and transfers articles between the carrier and the shelf at a predetermined position in the shelf extending direction (for example, refer to Patent Literature 1).

Citation List

Patent Literature

Patent Literature 1: Japanese Patent 5578278

Summary of Invention

Technical problem

In order to store different-sized articles in the above automated warehouse, for example, a distance between two shelves in a height direction (hereinafter, referred to as 'storage height') is changeable in accordance with an article size. However, a change of the storage height in accordance with the article size will limit the size of article to be stored onto each shelf.
In the automated warehouse with a carrier installed at each shelf, in a case where the size of an article capable of being stored at each shelf is limited and, for example, only a specific-sized article is required to be continuously stored onto an automated warehouse, only a carrier, which is placed on a shelf storing the specific-sized articles, works, while other carriers do not work. Thus, the throughput performance of the article handling decreases in the conventional automated warehouse system.
An objective of the present invention is to prevent an excessive access to a carrier installed on a specific shelf while providing shelves in accordance with the article size in an automated warehouse with a carrier installed at each shelf .

Solution to problem

As a means to solve the above issue, a plurality of aspects will now be described below. Any combination of these aspects can be used as appropriate.
The automated warehouse according to one aspect of the present invention includes shelves, carriers, an elevator, and a controller.
A plurality of shelves are provided.
The carrier is installed on each of the shelves and carries an article.
The elevator moves the article up or down.
The controller controls the carrier and the elevator to store/retrieve the article onto/from each of the shelves. The shelves include first shelves and second shelves. The first shelves stores first articles and the second shelves, which are larger than the first shelves, can store the first articles and second articles. In a case where a vacancy rate of the second shelf is equal to or more than a predetermined ratio, the controller allows the carrier and the elevator to store the first article also onto the second shelf. In a case where the vacancy rate of the second shelf is less than the predetermined ratio, the controller controls the carrier and the elevator to store the first article only onto the first shelf.
The above automated warehouse includes a plurality of the first shelves and a plurality of the second shelves. The second shelf is larger than the first shelf. The first shelf stores first small articles and the second shelf stores both, the first articles and the second articles larger than the first articles. Therefore, different-sized articles, such as the first articles and the second articles, can be stored on the shelves provided in accordance with the article size.
In addition, the first articles can be stored on the second shelf capable of storing the second larger articles. Thus, the first articles can be stored on all of the shelves.
In a case where the vacancy rate of the second shelf is equal to or more than the predetermined ratio, the controller allows the carrier and the elevator to store the first articles also onto the second shelf. In a case where the vacancy rate of the second shelf is less than the predetermined ratio, the controller controls the carrier and the elevator to store the first article only onto the first shelf.
Thereby, in the above-described automated warehouse, in a case where only a plurality of first articles are requested to be continuously stored onto shelves and the vacancy rate of the second shelf is equal to or more than the predetermined ratio, the controller can control also the carrier installed on the second shelf to operate in order to store the first articles onto the second shelf. As a result, excessive access to the carrier installed on the first shelf in order to carry and transfer articles can be prevented.
In a case where the same kinds of articles as the articles to be retrieved are stored on both of the first shelf and the second shelf, the controller may control the carrier and the elevator to retrieve the articles from the second shelf. This prevents the second shelf from being filled with the first articles and ensures a space to store the second article onto the second shelf.
The elevator preferably has an elevating platform capable of holding and lifting/lowering a plurality of articles. In this case, in a case where at least one of the plurality of the articles held by the elevating platform is the second article, the controller may control the carrier and the elevator to store also the remaining articles onto the second shelf. Thereby, the second article that cannot be stored onto the first shelf and other articles are stored onto the second shelf together, so that the frequency of stoppage at each shelf and/or the movement distance of the elevator can be reduced.
The elevator may have the elevating platform capable of holding and lifting/lowering a plurality of articles. In this case, in a case where it is known, in storing a specific article, that other articles to be retrieved together with the specific article are stored on the second shelf at present, the controller may control the carrier and the elevator to store the specific article onto the second shelf on which the other articles are stored.
Thereby, the specific article and other articles can be carried by the elevator at the same time so as to retrieve these articles together, so that the elevator can be efficiently used.
A 'group retrieval' means to retrieve a plurality of articles designated by the predetermined standard. In order to perform the group retrieval, the controller may control the carrier and the elevator to perform the group retrieval preferentially on a group including articles being stored on the second shelf among a plurality of groups subject to the group retrieval. Thereby, the second shelf can surely store the second articles without being filled with the first articles.
If a group to be retrieved includes any articles being stored on the second shelf, the controller may control the carrier and the elevator to preferentially retrieve the articles from the second shelf. Thereby, the second shelf can surely store the second articles without being filled with the first articles.
A control method according to another aspect of the present invention is a control method of an automated warehouse including shelves, carriers, and an elevator. The shelves include a first shelf storing a first article and a second shelf which is larger than the first shelf and capable of storing the first article and a second article larger than the first article.
One of the carriers is installed on each shelf and carries articles.
The elevator moves articles up and down.
The control method of the automated warehouse includes the following steps of:

allowing the first article to be stored onto the second shelf in a case where a vacancy rate of the second shelf is equal to or more than a predetermined ratio,
determining the first article to be stored only onto the first shelf in a case where the vacancy rate of the second shelf is less than the predetermined ratio, and
causing the carrier and the elevator to store the first article onto the first shelf or the second shelf onto which the first article was determined to be stored.

In the above control method of the automated warehouse, it is determined that the first article is allowed to be stored onto the second shelf in a case where the vacancy rate of the second shelf is equal to or more than the predetermined ratio, and the first article is stored onto only the first shelf in a case where the vacancy rate of the second shelf is less than the predetermined ratio.
Thereby, in the above automated warehouse, for example, in a case where a plurality of the first article are requested to be continuously stored and the vacancy rate of the second shelf is equal to or more than the predetermined ratio, the controller allows also the carrier installed on the second shelf to operate so as to store the first articles onto the second shelf. As a result, excessive access to a carrier installed on the first shelf to carry and transfer articles can be prevented.
A program according to yet another aspect of the present invention makes a computer execute the above method.
An automated warehouse system according to yet another aspect includes a first automated warehouse, a second automated warehouse, and a controller.
The first automated warehouse includes a third shelf storing a third article and a first carrier to carry the third article.
The second automated warehouse includes a fourth shelf, which is larger than the third shelf and capable of storing the third article and a fourth article, and a second carrier capable of carrying the third article and the fourth article. The fourth article is larger than the third article.
The controller controls the first carrier and the second carrier.
In a case where a vacancy rate of the fourth shelf is equal to or more than a predetermined ratio, the controller allows the second carrier to store the third article also onto the fourth shelf, and in a case where the vacancy rate of the fourth shelf is less than the predetermined ratio, the controller allows the first carrier to store the third article only onto the third shelf.
In the above automated warehouse system, in a case where the vacancy rate of the fourth shelf of the second automated warehouse is equal to or more than the predetermined ratio, the controller allows the second carrier to store the third article also onto the fourth shelf, and in a case where the vacancy rate of the fourth shelf is less than the predetermined ratio, the controller controls the second carrier to store the third article only onto the third shelf of the first automated warehouse.
With this configuration, in the above automated warehouse, for example, in a case where a plurality of the third articles are requested to be continuously stored and the vacancy rate of the fourth shelf is the predetermined ratio or more, the controller allows also the second carrier to operate in order to store the third article onto the fourth shelf. As a result, excessive access to the first carrier in order to carry articles can be prevented.

Advantageous Effects of Invention

In the automated warehouse according to the present invention, shelves can be provided in accordance with the size of articles to be stored and the excessive access to a specific carrier in the automated warehouse can be prevented.

Brief Description of the Drawings

FIG.1 is a top view of an automated warehouse.

FIG.2 is a side view of the automated warehouse.
FIG.3 is a perspective view of a carrier and a shelf.
FIG.4 is a flowchart showing a storing operation performed in the automated warehouse.
FIG.5 is a flowchart showing a retrieving operation performed in the automated warehouse.
FIG.6 is a flowchart showing a group retrieval performed in the automated warehouse.
FIG.7 is a flowchart showing a retrieval operation in a group performed in the automated warehouse.
FIG.8 is a drawing showing entire configurations of automated warehouse system according to a second embodiment.

Detailed Description of the Preferred Embodiments

1. First embodiment

(1) Automated warehouse

With reference to FIGS.1 to 3, an automated warehouse 100 according to a first embodiment will be now described as follows. FIG.1 is a top view of the automated warehouse. FIG.2 is a side view of the automated warehouse. FIG.3 is a perspective view of carriers and shelves. Hereinafter, the right and left direction of FIG.1 is referred to as an X direction, the vertical direction of FIG.1 is referred to as a Y direction, and the vertical direction of FIG. 2 is referred to as a Z direction (height direction). The automated warehouse 100 is a system that has a plurality of shelves and that is capable of storing articles onto each shelf or retrieving the stored article from each shelf. The automated warehouse 100 is provided with a rack 1, a plurality of carriers 3, an elevator 5, and a controller 9.

(2) Rack

The rack 1 includes a plurality of first shelves 11a and a plurality of second shelves 11b.
The first shelves 11a are disposed at a first interval in Z direction at the upper part of the rack 1. Thereby, the first shelves 11a form a first shelf group 13a at the upper portion of the rack 1. According to the present embodiment, the rack 1 includes six first shelves 11a, and, as a result, the rack 1 includes six first shelf groups 13a.
Each of the plurality of first shelf groups 13a has a storage height of the first interval and is capable of storing only smaller and shorter articles W1.
According to the present embodiment, as shown in FIGS.1 and 3, the rack 1 is installed at one side of the carrier 3 (rail 3a) in Y direction, but it is not limited thereto. The rack 1 may be installed at both sides of the carrier 3 (rail 3a) in Y direction.
A plurality of the second shelves 11b are arranged at the lower part of the rack 1 in Z direction at a second interval which is larger than the first interval. Thereby, the plurality of the second shelves 11b form a second shelf group 13b at the lower portion of the rack 1. According to the present embodiment, the rack 1 includes four second shelves 11b, as a result, the rack 1 includes four second shelf groups 13b.
The storage height of the second shelf group 13b is the second interval which is larger than the first interval and is higher than the storage height of the first shelf group 13a. That is, according to the present embodiment, the second shelves 11b can store both a larger and higher second article W2 and a smaller and lower first article W1.
According to the present embodiment, a plurality of the first shelves 11a are provided at the upper part of the rack 1 and a plurality of the second shelves 11b are provided at the lower part of the rack 1, but it is not limited thereto. The first shelves 11a and the second shelves 11b may be arranged at any position. For example, the plurality of first shelves 11a may be arranged at the lower part of the rack 1 and the plurality of second shelves 11b may be arranged at the upper of the rack. Further, for example, the rack 1 may be divided into three parts: upper, middle, and lower parts, and the second shelves 11b may be arranged at the middle part and the first shelves 11a may be arranged at the upper and lower parts.

(3) Carrier

A plurality of the carriers 3 are capable of moving along the X direction at the corresponding height position of each of the first shelves 11a and the second shelves 11b. In particular, for example, the plurality of carriers 3 are shuttle carriers to move back and forth along the X direction on the rail 3a placed at a corresponding height of each shelf. Each carrier 3 has a transfer device (not shown) so as to transfer an article from/onto the corresponding shelf.
With the above structure, each of the carriers 3 moves in the X direction on the first shelf 11a or the second shelf 11b on which each carrier is located, while holding the first article W1 or the second article W2, so as to carry the first article W1 or the second article W2 being held by each in the X direction. Further, the first article W1 or the second article W2 can be transferred from/onto the first shelf 11a or the second shelf 11b corresponding to each carrier 3 using the transfer device provided at each carrier 3.
The size of each of the plurality of carriers 3 may be changed in accordance with the size of the article to be carried by itself. For example, a carrier 3 which is arranged corresponding to the first shelf 11a so as to transfer the first article W1 may be smaller than a carrier 3 which is arranged corresponding to the second shelf 11b so as to transfer the second article W2. Thereby, the carrier 3 arranged corresponding to the first shelf 11a can be compact.

(4) Elevator

An elevator 5 is installed between the rack 1 and a storage/retrieval station 7 and includes an elevating platform 53, which can elevate along masts 51 in the Z direction while holding a plurality of articles. The elevating platform 53 includes the transfer device such as a conveyor to transfer the first article W1 and/or the second article W2 between the storage/retrieval station 7 and the first shelf 11a or the second shelf 11b.
With this configuration, the first article W1 and/or the second article W2 can be transferred from the storage/retrieval station 7 to the elevating platform 53. Vice versa, the first article W1 and/or the second article W2 held by elevating platform 53 can be transferred to the storage/retrieval station 7.
The first article W1 and/or the second article W2 being placed in the vicinity of the elevator 5 of the first shelf 11a or the second shelf 11b can be transferred to the elevating platform 53, vice versa, the first article W1 and/or the second article W2 being held by the elevating platform 53 to the vicinity of the elevator 5 of the first shelf 11a or the second shelf 11b.
As shown in FIG.2, the elevating platform 53 according to the present embodiment can hold a plurality of articles. This eliminates the need for operations to move the elevating platform 53 down to the storage/retrieval station 7, transfer an article between the storage /retrieval station 7 and the elevating platform 53, and then move it up again for each article.

(5) Controller

The controller 9 manages the storage and the storage/retrieval of articles in the automated warehouse 100, and controls the plurality of carriers 3 and the elevator 5 to perform storing or retrieving operations of articles W. The controller 9 is a computer system including a processor such as a CPU, a memory device, such as ROM, RAM, HDD or SSD, and various interfaces, such as A/D converter, D/A converter, or a communication interface.
The controller 9 may control each part by executing a program stored in a memory (corresponding to a part or all of a memory area of a memory device) or may perform a part of control operations by hardware included therein.
The controller 9 may be actualized with a single computer system or a plurality of computer systems. In case of being actualized with the plurality of computer systems, for example, the controller 9 may include a host controller to manage the operation of automated warehouse 100 such as storage and storage/retrieval of articles performed in the automated warehouse 100, a controller to control traveling of each carrier 3, and a controller to control a vertical movement of the elevating platform 53 of the elevator 5.

(6) Storage/retrieval operation in automated warehouse

(6-1) Storage operation

Hereinafter, with reference to FIG.4, operations performed by the automated warehouse 100 according to the first embodiment will now be described. FIG.4 is a flowchart showing an operation of article storage in the automated warehouse 100.
From the data showing the schedule of article storage, the controller 9 preliminarily obtains information when and how the storage operation is performed during operations of the automated warehouse 100.
In response to a transfer of the article to be stored from the storage/retrieval station 7 to the vicinity of the elevator 5, the controller 9 judges at step S1 whether all of the articles to be stored are the second article W2 or not. "All of the articles to be stored are the second article W2" means, if a single article is to be stored, the article would be the second article W2, and if a plurality of articles are to be stored, all of them would be the second articles W2.
In a case where all of the articles to be stored are the second articles W2 ('Yes' at step S1), the process goes to step S9, where the controller 9 determines that the second articles W2 will be stored onto the second shelf 11b.
The controller 9 may determine, for example, that the second article W2 to be stored will be stored onto the second shelf 11b with the highest vacancy rate (to be described later), that is, with the largest space of the plurality of second shelf 11b, or may determine that the second article W2 will be stored onto the second shelf 11b by selecting the second shelf 11b in order from the top or from the bottom of the rack 1. Further, for example, the controller 9 may determine that the second article W2 will be stored on the second shelf 11b provided with a carrier 3 the operation time of which is the shortest.
Whereas, in a case where the articles to be stored are not only the second articles W2, that is, include a first article W1 ('No' at step S1), the controller 9 further determines at step S2 whether the articles to be stored include only a first article W1 or both a first article W1 and a second article W2. In a case where a single article is to be stored, the above step S2 and step S6 to S8 are not executed. Because, in a case where the single article is judged not to be the second article W2 at step S1, the article is determined to be only the first article W1.

(6-1-1) In case only the first article to be stored

How to determine the target shelf in a case where the article to be stored is only the first articles W1 will now be described.
In a case where the article to be stored is only the first article W1 ('Yes' at step S2), the controller 9 judges at step S3 whether the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio or not. The 'Vacancy rate' of the second shelf 11b can be defined as the ratio of the number of articles capable of being further stored to the total number of articles capable of being stored onto a second shelf 11b. In addition, the 'vacancy rate' may be defined as, for example, the ratio of area of the second shelf 11b on which articles can be further placed to the total area of the second shelf 11b on which articles can be placed. The 'predetermined ratio' which is a threshold of the 'vacancy rate' may be defined as, for example, a fixed value such as 50%.
As another preferred embodiment, the above 'predetermined ratio' may be appropriately changed into a value predicted on the basis of the past results of the stored articles (for example, the number of the second articles W2 stored per day or per month) and the present situation of storage. For example, as the vacancy rate of the first shelf 11a becomes lower, the above 'predetermined ratio' may be lowered. In this way, as the vacancy rate of the first shelf 11a becomes lower, the above 'predetermined ratio' is lowered, whereby the first smaller articles W1 can be stored more than the number of the articles W1 stored onto the first shelf 11a.
In a case where it is judged that the articles to be stored are only the first articles W1 and the vacancy rate of the second shelf 11b is less than the predetermined ratio ('No' at step3), the controller 9 determines at step S4 that the first articles W1 to be stored will be stored only onto the first shelf 11a. Which first shelf 11a of a plurality of first shelves 11a the first article W1 will be stored onto can be determined in the same way as the above-described step S9.
In a case where it is judged that the articles to be stored are only the first articles W1 and the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio ('Yes' at step S3), the controller 9 determines at step S5 that the first articles W1 can be stored onto both the first shelf 11a and the second shelf 11b. That is, the controller 9 allows the carrier 3 and the elevator 5 to store the first article W1 also onto the second shelf 11b.
In this process, the controller 9 can determine that the first article W1 will be stored onto the shelf with the largest vacancy rate among the first shelves 11a and the second shelves 11b, that the first article W1 be stored onto the shelf selected in order from the top or the bottom of the rack 1, and that the first article W1 be stored onto the shelf with the carrier 3 the operation time of which is the shortest among all carriers 3 included in the automated warehouse 100.
Further, for example, the controller 9 may determine that the article is allowed to be stored onto the second shelf 11b in a case where the vacancy rates of all first shelves 11a are less than a certain threshold, that is, the available spaces of all first shelves 11a become small.
As described above, in a case where the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio, the controller 9 of the automated warehouse 100 determines that the first article W1 can be stored also onto the second shelf 11b, and in a case where the vacancy rate is less than the predetermined ratio, the controller 9 determines that the first article W1 can be stored only onto the first shelf 11a.
Thereby, in the automated warehouse 100 according to the present embodiment, for example, in a case where only a plurality of the first article W1 are requested to be continuously stored and the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio, the controller 9 can control the carriers 3 installed on the second shelves 11b to operate so as to store the first article W1. As a result, excessive access to the carrier 3 installed on a first shelf 11a in order to carry and transfer articles can be prevented.

(6-1-2) In case the first article and the second article to be stored

How to determine the target shelf in a case where a plurality of articles to be stored are mixtures of both the first article w1 and the second article W2 will now be described. In a case where mixtures of both the first article w1 and the second article W2 are stored ('No' at step S2), the controller 9 judges at step S6 whether the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio or not. Operations performed at step S6 is the same as those of step S3 described above and thus a detailed explanation is omitted.
In a case where articles to be stored are mixtures of both the first article W1 and the second article W2 and the vacancy rate of the second shelf 11b is less than the predetermined ratio ('No' at step S6), the controller 9 determines at step S7 that the first article W1 and the second article W2 of articles to be stored be stored onto the first shelf 11a and the second shelf 11b, respectively.
Whereas, in a case where the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio ('Yes' at step S6), the controller 9 determines at step S8 that both the first article W1 and the second article W2 be stored onto the same second shelf 11b
In a case where the controller 9 determines that both the first article W1 and the second article W2 are stored onto the same second shelf 11b, the first article W1 and the second article W2 to be stored onto the same second shelf 11b are held by the elevating platform 53 in the elevator 5 at a time and carried to the targeted second shelf 11b with the elevating platform 53 at a time in the storage process of step S10 (to be described later).
As described above, in the present embodiment, in a case where at least one of a plurality of articles held by the elevating platform 53 is the second article W2, the controller 9 determines that the remaining first articles W1 will be stored onto the same second shelf 11b. That is, the controller 9 determines a storing location based on the second article W2 that cannot be stored onto the first shelf 11a.
Thereby, the second article W2 that cannot be stored onto the first shelf 11a and the remaining first article W1 are stored onto the same second shelf 11b together. As a result, the frequency of the elevating platform 53 stopping at each shelf and/or the traveling distance of the elevating platform 53 can be reduced.
According to another embodiment, the controller 9 may determine at step S6 that the first article W1 and the second article W2 will be stored onto shelves close to each other. This also reduces the traveling distance of the elevating platform 53.
After the above steps S1 to S9 are executed to determine the shelves onto which the articles will be stored, at step S10, the controller 9 controls the carrier 3 and the elevator 5 to store the articles to be stored onto the determined shelves in accordance with the above determination. Operations to store articles are performed as follows.
In accordance with the controller 9, the elevating platform 53 of the elevator 5 lifts and lowers to a position of a transporting surface of the storage/retrieval station 7 and the articles to be stored are transferred from the storage/retrieval station 7 to the elevating platform 53 of the elevator 5. A plurality of articles to be stored, which are stacked on the storage/retrieval station 7, may be transferred to the elevating platform 53 at a time.
Next, in accordance with the controller 9, the elevating platform 53 holding the articles lifts and lowers to a position corresponding to the shelf onto which the articles to be stored were determined to be stored (hereinafter, referred to as 'target shelf') and the articles to be stored are transferred from the elevating platform 53 to the target shelf. If a plurality of articles to be stored are determined to be stored onto different shelves, respectively, the elevating platform 53 may stop at each target shelf and transfer each article thereto.
Then, in accordance with the controller 9, the carrier 3 installed on the target shelf moves to a position where the article to be stored is placed, and transfers the article to the carrier 3 from the target shelf.
In accordance with the controller 9, the carrier 3 installed on the target shelf and holding the article to be stored travels along the X direction, carries the article to the target position of the target shelf, and places the article onto the target shelf.

(6-2) Retrieval operation

The retrieval operations performed in the automated warehouse 100 will be described. From the data showing a retrieval schedule or the like, the controller 9 preliminarily obtains information on which articles are to be retrieved and in a case where the articles are to be retrieved during operations of the automated warehouse 100.
In response to a start of the retrieval operations, the controller 9 determines whether 'group retrieval' will be performed or not on the article to be retrieved shown in the retrieval schedule. The 'group retrieval' is a method to retrieve a plurality of articles designated based on the predetermined standard as a group. In this group retrieval, articles within a group may be retrieved in any order.
In a case where the group retrieval is not performed, the controller 9 controls the carrier 3 and the elevator 5 to retrieve articles to be retrieved in accordance with the flowchart shown in FIG.5, which shows retrieval operations without performing the group retrieval. Whereas, in a case where the group retrieval is performed, the controller 9 controls the carrier 3 and the elevator 5 to retrieve articles to be retrieved in accordance with the flowchart shown in FIG.6, which shows group retrieval operations.

(6-2-1) retrieval operations without performing group retrieval

Hereinafter, with reference to FIG.5, the detailed retrieval operations without group retrieval will now be described.
In response to a start of a retrieval operation, which shelf an article is retrieved from is determined. In particular, the controller 9 judges at step S11 whether the article to be retrieved is a first article W1 or not. In a case where the article to be retrieved is a second article W2 ('No' at step S11), it is determined at step S15 that the second article W2 to be retrieved will be retrieved from a second shelf 11b.
In a case where the article to be retrieved is a first article W1 ('Yes' at step S11), the controller 9 determines at step 12 whether the same type of first articles W1 are stored on both of the first shelves 11a and the second shelves 11b. The above 'the same type of first articles W1' means, for example, a plurality of first articles W1 that have the same item code, the same expiry date, the same storing date, or the same production lot.
That is, in the present embodiment, the first articles W1 stored on the first shelf 11a and the first articles W1 stored on the second shelf 11b are considered as the same type of articles to be retrieved.
In a case where the same type of first articles W1 to be retrieved are stored only on the first shelf 11a ('No' at step S12), the controller 9 determines at step 13 that the first articles W1 will be retrieved from the first shelf 11a.
Whereas, in a case where the same kind of first articles W1 to be retrieved are stored on both of the first shelf 11a and the second shelf 11b ('Yes' at step S12), the controller 9 determines at step S14 that the first article W1 will be retrieved from the second shelf 11b.
As described above, in a case where the same kind of first articles W1 as the article to be retrieved are stored on both of the first shelf 11a and the second shelf 11b, the first article W1 is retrieved from the second shelf 11b preferentially, thereby, the space of the second shelf 11b can be ensured. Therefore, for example, the second shelf 11b is sure to store the second articles W2 without being filled with the first article W1.
After determining from which shelf an article will be retrieved, the controller 9 controls the carrier 3 and the elevator 5 to retrieve the article from the determined shelf at step S16. Operations performed to retrieve an article to be retrieved at step 16 will now be described in detail as follows:
The controller 9 controls so that the carrier 3 installed on the retrieving target shelf which was determined for an article to be retrieved at step S11 to S15 can move to a position where the article to be retrieved is placed and transfer the article from the shelf.
Next, the controller 9 controls to move the carrier 3 holding the article to the vicinity of the elevator 5 and to transfer the article to be retrieved to the retrieving target shelf from the carrier 3 at the position. Then, the controller 9 controls the elevator 5 to transfer the article to be retrieved from the retrieving target shelf to the elevating platform 53.
Finally, the controller 9 makes the elevating platform 53 holding the article to be retrieved to move to the storage/retrieval station 7 and the article to be retrieved is transferred from the elevating platform 53 to the storage/retrieval station 7. If a plurality of articles to be retrieved have already been transferred onto the corresponding shelf, the controller 9 may make the elevating platform 53 hold the plurality of articles to be retrieved.
Until all of the articles instructed to be retrieved have been retrieved (until 'Yes' is selected at step S17), the above steps S11 to S16 are repeatedly carried out in the instructed order. That is, in a case where the group retrieval is not performed, a plurality of articles to be retrieved are retrieved sequentially in the order of a retrieval instruction.
During the retrieving operations performed from step S11 to S17, the order of retrieval may be determined by raising the priority of the articles to be retrieved from the second shelf 11b. For example, the articles may be retrieved from the second shelf 11b preferentially.

(6-2-2) retrieval operations with performing group retrieval

With reference to FIG.6, retrieval operations with performing group retrieval will now be described.
In response to a start of the group retrieval, the controller 9 identifies a group as a unit of the group retrieval at step S21. In particular, the controller 9 identifies a plurality of articles for the same customer as a group in the group retrieval, for example.
Further, for example, a plurality of articles determined per destination area, per arrival time at destination, or per a same delivery vehicle, such as a truck, may be identified as a group.
Next, the controller 9 determines at step S22 whether the group retrieval will be performed on a plurality of groups or not. If the group retrieval is performed on a single group ('No' at step S22), a 'retrieval in a group' is performed on this one group at step S23. The 'retrieval in a group' is referred to as a retrieval of an article included in one group. How the automated warehouse 100 performs operations of the retrieval in a group will be described later.
Whereas, if the group retrieval is performed on a plurality of groups ( 'Yes' at step S22), at step S24, the controller 9 determines which group of the plurality of groups is preferentially retrieved.
Specifically, the controller 9 determines a group that has not been selected as a retrieving target and includes the maximum number of articles (first article W1 and/or second article W2) being stored on the second shelf 11b to be a target group of retrieval. That is, the controller 9 makes a group including the maximum number of articles and being stored on the second shelf 11b become a target of retrieval.
After determining a target group of retrieval from a plurality of groups, the controller 9 controls the carrier 3 and the elevator 5 at step S25 to perform the retrieval in a group on the selected group. The retrieval operation in a group performed at step S25 is the same as that at step S23.
The above-described operations of step S24 and S25 are repeatedly carried out until all of the plurality of groups have been retrieved (until 'Yes' is selected at step S26).
The above steps S21 to S26 are carried out to perform a group retrieval preferentially on the group having articles being stored on the second shelf 11b. Therefore, the second shelf 11b is sure to store the second articles W2 without being filled with the first article W1.

(6-2-3) Retrieving operation in a group

Next, with reference to FIG.7, the specific operations of the automated warehouse 100 (carrier 3 and elevator 5) for the retrieval in a group performed at step S23 and S25 in the flowchart shown in FIG.6 will be described as follows.
FIG.7 is a flowchart showing the retrieval in a group performed in the automated warehouse 100.
In response to starting of the retrieval in a group, the controller 9 determines at step S31 whether articles (the first article W1 and/or the second article W2) stored in the second shelf 11b are included or not in articles that are included in a group to be retrieved and have not been retrieved (referred to as articles awaiting retrieval').
If the articles awaiting retrieval include articles being stored on the second shelf 11b, ('Yes' at step S31), the controller 9 controls the carrier 3 and the elevator 5 at step S32 to retrieve the articles being stored on the second shelf 11b. The details of operations to retrieve articles were described above and thus are omitted herein.
If the articles awaiting retrieval do not include articles being stored on the second shelf 11b, ('No' at step 31), the controller 9 controls the carrier 3 and the elevator 5 at step S33 to retrieve the first article W1 being stored on the first shelf 11a.
The above-described steps S31 to S33 are repeatedly carried out until articles of all groups to be retrieved have been retrieved (until 'Yes' is selected at step S34).
If there are any articles stored in the second shelf 11b in a group including the plurality of articles to be retrieved, the articles stored in the second shelf 11b can be preferentially retrieved by carrying out the above-described steps S31 to S34. Therefore, the second shelf 11b is sure to store the second articles W2 without being filled with the first articles W1.

(7) Features of first preferred embodiment

The above first embodiment will be also described as follows:
An automated warehouse 100 (an example of an automated warehouse) includes a first shelf group 13a, a second shelf group 13b (an example of a shelf), a carrier 3 (an example of a carrier), an elevator 5 (an example of an elevator), and a controller 9(an example of an controller).
The first shelf group 13a and the second shelf group 13b are made up of a plurality of shelves.
The carrier 3 is provided on each shelf and carries articles.
The elevator 5 moves articles up and down.
The controller 9 controls the carrier and the elevator to store or retrieve articles onto or from the shelf.
The shelf of the automated warehouse system includes the first shelves 11a (example of a first shelf) and the second shelves 11b (example of a second shelf). The first shelves 11a store first articles W1. The second shelves 11b, which are larger than the first shelves 11a, are capable of storing the first articles W1 and second articles W2.
In a case where the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio, the controller 9 allows the carrier 3 and the elevator 5 to store the first article W1 onto the second shelf 11b.
Whereas, in a case where the vacancy rate of the second shelf 11b is less than the predetermined ratio, the controller 9 controls the carrier 3 and the elevator 5 to store the first articles W1 only onto the first shelves 11a.
In the automated warehouse 100, in a case where the vacancy rate of second shelf 11b is equal to or more than the predetermined ratio, the controller 9 allows the carrier 3 and the elevator 5 to store a first article W1 also onto the second shelf 11b. In a case where the vacancy rate of the second shelf 11b is less than the predetermined ratio, the controller 9 controls the carrier 3 and the elevator 5 to store first articles W1 only onto the first shelves 11a.
Thereby, in the automated warehouse 100, for example, in a case where only a plurality of first articles W1 are requested to be continuously stored and the vacancy rate of the second shelf 11b is equal to or more than the predetermined ratio, the controller 9 controls the carrier 3 installed on the second shelve 11b to operate so as to store the first articles W1 onto the second shelves 11b. As a result, excessive access to the carrier 3 installed on the first shelf 11a in order to carry and transfer articles can be prevented

2. Second embodiment

The storage control of the first article W1 and the second article W2 described in the first embodiment is also applicable to another automated warehouse (automated warehouse system). For example, the storage control of the first article W1 and the second article W2 described in the first embodiment is applicable to an automated warehouse system 200 described in FIG.8. FIG.8 shows an entire configuration of the automated warehouse system 200 according to the second embodiment.
Hereinafter, with reference to FIG.8, the automated warehouse system 200 according to the second embodiment will now be described. The horizontal direction of FIG.8 is referred to as a X direction and the vertical direction of FIG.8 is referred to as a Y direction. The direction perpendicular to the X direction and the Y direction is referred to as a height direction.
The automated warehouse system 200 includes a first automated warehouse 101, a second automated warehouse 103, and a controller 105.
The first automated warehouse 101 stores a third article W3. Specifically, the first automated warehouse 101 includes a plurality of third shelves 101a and a first carrier 101b. The third shelf 101a extending to the X direction is capable of placing the third small article W3. The plurality of third shelves 101a are arranged at both sides of the first carrier 101b side by side in the Y direction and/or arranged at a sufficient interval to store the third article W3 in the height direction.
The first carrier 101b is a carrying device which has an transfer device capable of transferring the third article W3 between the third shelf 101a and the first carrier 101b and travels along the third shelf 101a extending direction (the X direction) to carry the third article W3. The first carrier 101b is, for example, a stacker crane.
The second automated warehouse 103 is capable of storing both of the third article W3 and a fourth article W4 larger than the third article W3. In particular, the second automated warehouse 103 has a plurality of fourth shelves 103a and second carriers 103b. The fourth shelf extending in the X direction is capable of placing both of the third article W3 and the fourth article W4. The plurality of fourth shelves 103a are arranged at both sides of the second carrier 103b side by side in the Y direction and/or arranged at a sufficient interval to store the third article W3 and the fourth article W4 in the height direction.
The second carrier 103b is a carrying device which has a transfer device capable of transferring the third article W3 and the fourth article W4 between the fourth shelf 103a and the second carrier 103b and travels along an extending direction (the X direction) of the fourth shelf 103a to carry the fourth article W4. The second carrier 103b is, for example, a stacker crane.
The controller 105 manages the custody and the storage/retrieval of the third article W3 and the fourth article W4, and controls the first carrier 101b and the second carrier 103b to store or retrieve the third article W3 and the fourth article W4.
The controller 105 is a computer system including a processor, such as CPU, a memory such as ROM, RAM, HDD, or SSD, and an interface, such as A/D convertor, D/A convertor, or a communication interface.
The automated warehouse system 200 includes a conveyor 107 that carries the third article W3 and the fourth article W4 between a storage/retrieval station 109, the first automated warehouse 101 (the third shelf 101a), and the second automated warehouse 103 (the fourth shelf 103a).
In the automated warehouse system 200 with the above configuration, in a case where the vacancy rate of the fourth shelf 103a is equal to or more than the predetermined ratio, the controller 105 allows the second carrier 103b to store the third article W3 also onto the fourth shelf 103a.
In a case where the vacancy rate of the fourth shelf 103a is less than the predetermined ratio, the controller 105 allows the first carrier 101b only to store the third article W3 onto the third shelf 101a without allowing the second carrier 103b to store the third article W3 onto the fourth shelf 103a.
With this configuration, in the automated warehouse system 200 according to the second embodiment, for example, in a case where only a plurality of the third article W3 are requested to be continuously stored and the vacancy rate of the fourth shelf 103a is equal to or more than the predetermined ratio, the controller controls not only the first carrier 101b but also the second carrier 103b so as to store the third article W3 onto the fourth shelf 103a. As a result, an excessive access to the first carrier 101b in order to carry the third article W3 can be prevented.

3. Another embodiment

A plurality of embodiments of the present invention are described above, however, the present invention is not limited to the above embodiments. Various changes can be made without departing from the scope of the invention. A plurality of the embodiments and variations described herein may be combined as appropriate.

(A) The order and/or the process of each step of the flowcharts shown in FIGS.4 to 7 may be changed within the scope of the invention in an appropriate manner.
(B) According to the first preferred embodiment, the first shelf 11a stores the first lower article W1 and the second shelf 11b stores the second higher article W2. However, it is not limited thereto. Even when specific shelves in accordance with the width of articles (for example, a shelf for wide articles or a shelf for narrow articles) are provided, the above-described methods of storing and retrieving article are applicable.
In this case, the control 9 may determine which shelf an article is stored and/or retrieved onto/from, on the basis of the width of the article. Further, the controller 9 may determine the shelf onto/from which an article is stored and/or retrieved in view of both of the height and width of the article.
(C) In the first embodiment and the second embodiment, the 'Vacancy rate' is defined as the ratio of the number of articles capable of being further stored into a second shelf to the total number of articles capable of being stored in the second shelf or is defined as, for example, the ratio of area on which articles can be further placed to the total area of the second shelf 11b on which articles can be placed.
However, it is not limited thereto. The controller 9 may determine whether the first article W1 is allowed or not to be stored onto the second shelf in accordance with a number defined based on the vacancy rate. For example, the number of articles capable of being further stored onto the second shelf, or the number of vacant second selves with no articles placed can be used as the number defined based on the vacancy rate.
(D) Even if a priority per group is not determined during the group retrieval, the articles being stored on the second shelf 11b may be determined to be preferentially retrieved during the retrieval in each group.
(E) In the automated warehouse 100 according to the first embodiment and the automated warehouse system 200 according to the second embodiment, in addition to small articles (first articles W1, third articles W3) and large articles (second articles W2, fourth articles W4), articles intermediate between the small articles and the large articles may also be capable of being stored and retrieved. These medium-sized articles may include various-sized articles. In this case, two or more types of shelves may be provided at the rack in accordance with an article capable of being stored or retrieved.
(F) If it is known, in storing a specific article, that another article to be retrieved with the specific article during a retrieval operation is stored on a second shelf 11b at present, the controller 9 may control the carrier 3 and the elevator 5 so that the specific article can be stored onto the second shelf 11b on which the other article is stored.
This enables the above-described specific article and the other article to be carried by the elevator 5 at a time when these two articles are retrieved together. As a result, the elevator 5 can be used efficiently during the retrieval operation.
(G) The group of the group retrieval may include a single article.

The present invention is widely applicable to automated warehouse systems where a plurality of shelves to store articles are provided and carriers to carry articles are provided at each shelf.

Reference Signs List

100: Automated warehouse
1: Rack
3: Carrier
3a: Rail
5: Elevator
51: Mast
53: Elevating platform
7: Storage/retrieval station
9: Controller
11a: First shelf
11b: Second shelf
13a: First shelf group
13b: Second shelf group
W1: First article
W2: Second article
200: Automated warehouse system
101: First automated warehouse
101a: Third shelf
101b: First carrier
103: Second automated warehouse
103a: Fourth shelf
103b: Second carrier
105: Controller
107: Conveyor
109: Storage/retrieval station
W3: Third article
W4: Fourth article

Claims

An automated warehouse comprising:
a plurality of shelves;

a carrier installed on each of the shelves and carrying an article;

an elevator moving the article up or down; and

a controller controlling the carrier and the elevator to store/retrieve the article onto/from each of the shelves,

wherein the shelves include first shelves storing first articles and second shelves larger than the first shelves and capable of storing the first articles and second articles larger than the first articles, and

in a case where a vacancy rate of the second shelf is equal to or more than a predetermined ratio, the controller allows the carrier and the elevator to store the first article also onto the second shelf, and in a case where the vacancy rate of the second shelf is less than the predetermined ratio, the controller controls the carrier and the elevator to store the first article only onto the first shelf.
The automated warehouse according to claim 1, wherein in a case where the same kinds of articles as the articles to be retrieved are stored on both of the first shelf and the second shelf, the controller controls the carrier and the elevator to retrieve the articles from the second shelf.
The automated warehouse according to claim 1, wherein the elevator has an elevating platform capable of holding and lifting/lowering a plurality of articles, and in a case where at least one of the plurality of articles held by the elevating platform is the second article, the controller controls the carrier and the elevator to store also the remaining articles onto the second shelf.
The automated warehouse according to claim 1,
wherein the elevator has an elevating platform capable of holding and lifting/lowering a plurality of articles, and

in a case where it is known, in storing a specific article, that other articles to be retrieved together with the specific article to be stored are stored on the second shelf at present, the controller controls the carrier and the elevator to store the specific article onto the second shelf where the other articles are stored.
The automated warehouse according to claim 1,
wherein, in order to perform a group retrieval to retrieve a plurality of articles designated by a predetermined standard, the controller controls the carrier and the elevator to perform the group retrieval preferentially on a group having articles being stored on the second shelf among a plurality of groups subject to the group retrieval.
The automated warehouse according to claim 5, wherein if a group to be retrieved includes any articles being stored on the second shelf, the controller controls the carrier and the elevator to preferentially retrieve the articles from the second shelf.
A method of controlling an automated warehouse comprising:
shelves including first shelves storing first articles and second shelves larger than the first shelves and capable of storing the first articles and second articles larger than the first articles,

carriers arranged on each of the shelves and carrying the articles, and

an elevator moving the articles up and down,

the method comprising:
allowing the first article to be stored onto the second shelf in a case where a vacancy rate of the second shelf is equal to or more than a predetermined ratio;

determining the first article to be stored onto only the first shelf in a case where the vacancy rate of the second shelf is less than the predetermined ratio; and

causing the carrier and the elevator to store the first article onto the first shelf or the second shelf onto which the first article was determined to be stored.
A program to make a computer execute the method of controlling automated warehouse according to claim 7.
An automated warehouse system comprising:
a first automated warehouse including a third shelf that stores a third article and a first carrier that carries the third article;

a second automated warehouse including a fourth shelf larger than the third shelf and capable of storing the third article and a fourth article larger than the third article, and a second carrier capable of carrying the third article and the fourth article; and

a controller that controls the first carrier and the second carrier,

wherein, in a case where a vacancy rate of the fourth shelf is equal to or more than a predetermined ratio, the controller allows the second carrier to store the third article also onto the fourth shelf, and in a case where the vacancy rate of the fourth shelf is less than the predetermined ratio, the controller allows the first carrier to store the third article only onto the third shelf.